Question

Heterolytic fission of a covalent bond can form:
A.Free radical
B.Both carbocation and carbanion
C.Only carbocation
D.Only carbanion

Answer 1

Hint: To answer this question, you must recall the different types of breaking of existing chemical bonds during a chemical reaction. Bond fission can be either homolytic bond fission or heterolytic bond fission. Heterolytic fission is the cleavage of a chemical bond in which both the electrons taking part in bond formation are retained by only one of the atoms forming the bond.

Complete answer:
The covalent bond formed between two atoms, when breaks in a dissimilar way is said to have undergone heterolytic fission. In other words, heterolytic fission is the cleavage of a chemical bond in which both the electrons taking part in bond formation are retained by only one of the atoms forming the bond. This dissimilar fission results in the retention of the bond pair of electrons by one atom only. Thus, we can conclude that when a neutrally charged molecule undergoes heterolytic fusion, one of the products formed would be negatively charged while the other product would be positively charged.
The atom which does not retain any of the electrons of the bond pair forms the positively charged entity on heterolytic fission of the bond forming a cation. The atom which retains both the electrons of the bond pair forms the negatively charged entity on heterolytic cleavage and is known as the anion.
Thus, when a covalent carbon- carbon bond undergoes heterolytic cleavage, a carbocation and a carbanion are formed.

Thus, the correct answer is B.

Note:
A chemical bond can undergo a homolytic cleavage as well. Homolytic cleavage is also known as hemolysis. The bond cleavage occurs in an equal manner and each atom retains one electron. As a result of homolytic fission, two free radicals are obtained.